Valve mechanism



Oct. 13, 1959 G. T. RANDQL VALVE MECHANISM 2 Sheets-Sheet 1 v Filed June' 7, 1957 Oct.13, 1959 I G. T. RANQDOL' 2,908,253

VALVE MECHANISM Filed June 7, 1957 2 Sheets-Sheet 2 2,903,253 Patented Oct. 13, 1959 United States Patent Chips 2,908,253 VALVE MECHANISM Glenn T. Randol, Mountain Lake Park, Md. Application June 7, 1957, Serial No. 664,431

7 :12 Claims. or. 121-465) The present invention relates to improved novel valve mechanism designed for controlling a fluid circuit, said invention constituting animprovement related to the switch mechanism disclosed in U.S. Patent No. 2,716,678 granted to me August 30, 1955.

Broadly, this invention concerns a valve mechanism for selectively opening or closing a fluid circuit adapted to control the operation of a fluid pressure energizable apparatus or the like, the latter may be situated either approximately or remotely relatively to said mechanism.

More specifically, my invention is directed to the provision of new and novel valve mechanism operable in response to minute reciprocatory movements of an element which may be frictionally actuated, for example, by an automotive accelerator pedal, by a servomotor piston, by mechanical linkage, or by manualor speedresponsive means; said element being adapted to control, in a novel manner, movement of a compound assembly comprising a pair of engaging elements relatively movable with respect to each other and to a fixed element for effecting open and closed conditions of the mechanism.

Preferably, but not necessarily, the valve mechanism comprising the present invention is pivotally mounted,

so as to compensate readily for corresponding move-.

ments of a reciprocatable or oscillatable actuating ele-. ment, as will appear. I

The primary objects of my invention therefore, are the provision of a compact and simple valve mechanism responsive to minute reciprocative movements of a frictionally connected actuating element, for selectively closing and opening a fluid circuit at any point along'the full operating stroke of said element; the provision of means for suitably mounting said valve mechanism on a support to accommodate actuation thereof; the provision of means incorporated in said mechanism for accommoclating minute movements of the actuating element without affecting the then existent relative disposition of the circuit controlling elements; and the provision of means for normally maintaining the valve mechanism in circuit-open position.

A further and important object of the invention related to the series of primary objects immediately preceding, is the provision of valve means to accommodate a full operating stroke of the aotuatable element relative to either an open, or a closed position of an included movable element assembly, and wherein said movable assembly is operatable to open and closed positions substantially at all points along the full stroke of the actuatable element responsive to minute reciprocative movements of said element within itsropenating stroke aforesaid, thus to produce in effect, a follow-up control of the energization and de-energization of a device such as, for example, a fluid pressure-operated servomotor controlled by said means.

Another object relative to that immediately preceding,

is the provision of novel means to. enable continued movement of the actuatable element in one direction after the movable assembly has been moved to closed position, without affecting the closed disposition of the assembly; to enable continued movement of the actuatable element in the opposite direction after the movable assembly has been moved to open position, without alfecting the open disposition of the assembly; and to enable arrested movements of the actuatable element during the full operating stroke thereof in either direction, without alfecting the then obtaining disposition of said assembly.

A further and more specific object related to the two immediately preceding objects, resides in the utilization of an automotive vehicle engine accelerator mech anism as the personal responsive means for operating the actuatable element of the valve mechanism, the latter including means for accommodating the 'full stroke of the accelerator throughout its engine controlling range of movement, and adaptedresponsive to minute reciprocations of said accelerator transmit-ted to said actuatable element, to operate the valvemechanism for opening and closing the fluid pressure. circuit of a power device, whereby to control the operation thereof and thus provide in effect, a follow-up control therefor.

The present invention also contemplates novel utilization of a single movable element in lieu of the comto follow, features and advantages not specifically recited hereinbefore will be apparent or noted, reference being had also to the accompanying drawing in which the preferred embodiments of my invention are illustrated as described below:

Figure 1 is a diagrammatic layout of a servomotor control system wherein is incorporated the valve mechanism comprising the present invention;

Figure 2 is a longitudinal section on an enlarged scale of the valve mechanism per se shown in Figure 1;

Figure 3 is a vertical sectional view taken along the line 3-3 of Figure 2;

Figure 4 is a further enlarged reproduction of the major portion of Figure 2, the valve being shown in closed position; and v Figure 5 illustrates a modified form of the invention wherein the movable valve assembly comprises a single element shown in open position.

Like characters of reference designate like parts in the several views with like parts in the Figure 5 modification distinguished, however, by the addition of the letter a to each numeral and the exponent l to each letter.

The valve mechanism comprising the instant invention is designated in its entirety by the letters VM, and its incorporation in a' vacuum-actuated servomotor controlled system, generally designated SMC, has been resorted to for illustrating and explaining the new and novel construction and operation thereof.

The illustrated valve actuating element of said system comprises, by way of example, a rod 24 reciprocatable by means of a pedal such as an engine accelerator 26 for an automotive vehicle, in conjunction with a normally preloaded expansion spring 28 for opposing foot operation thereof, as should be apparent from an inspection of an exemplary installation shown in Figure 1.

It is here noted that the rod 24 typifies any similar reciprocatory element characterized by axial or rotational movement, either mechanically or manually actuatable to elfect the operation of the valve mechanism VM in a new and novel manner to be described.

The valvemechanism VM as seen to best advantage in Figures 1, 2, and 3, includes a cup-shaped casing generally designated C; a movable valve assembly generally 4'5"c0mprises: an inner terminating tubular body portion MA; a fixed valve assembly generally desigdesignated mechanism generally n'ated" FA; and asupport for the designated S.

The cup-shaped casing C includes a cylindrical body portion 30; an end wall 32; an externally projecting reduced tubular portion 34 integral with the latter terminating in an inturned right angle flange 35 formed-- with a coaxial right angle outt'urned" bearing collar 36", a plurality of atmospheric ports 37 circumferentially dis posed through the flange; an angular embossment extruded outwardly from the end wall between the body and tubular portions; a cup-shaped fitting 39 attached exteriorly to said embossment; a passageway through the end wall of the fitting communicating with: the interior of the casing; another cup-shaped fitting 41' secured to the exterior of the" cylindrical portion of the casing: medially thereof; a passageway 42 through the end wall of the latter fitting establishing communication: with the interior of the casing; and a plurality of holes 43 equally spaced circumferentially adjacent the open endof the cylindrical portion of the casing.

The movable assembly MA includes a pair of tele-" scopically related relatively movable poppet-type valve elements 44 45, the outer element 44 comprisinga tubular extension 46"'having alongitudinal bore 47 there-"i through and aplurality of coextensive longitudinal at mospheric channels 48' communicating with an internal annular space 49 at-the'in'n'er end formed in the cylindrical surface of the bore 47; an annular external flan'ge head Stlterminating' the inner end of extension 46; inner and outer concentric angular ring seats 52, 53 formed in the end surface of the flange 50 The inner'elernent 55*having a" longitudinal bore 56 and a tubular reduced? diameter extension 58 projecting from the other end through'the bore 47 and having a correspondingly re: duced longitudinal bore 59 coaxially disposed with" re spect to the bore 56- and collar 36; an internal annular shoulder 60' at the point of mergence of the bores'56'; 59; and an angular ring-type seat 62 defining an external annular shoulder between the exterior surfaces of the tubular-portion 55 and extension 58; an external annular channel 64 -providedin the exterior cylindrical" surface of the extension 58 adjacent the end thereof manor: mally sp'aced'f'rom'the endof the extension 46; a splittype retainer'ring 65 engaging said channel; ahelicall'y formed normally preloaded compression spring 66"en= circles the portion of the extension 58 projecting' beyond the extension46withthe opposite ends thereof reacting on the end of the extension 46 and retainer ring '65 to bias-:the inner and outer elements" away" from each other to intimately engage the concentric valve seats 52'; 62' in aintight sealed relationship best demonstrated in Figure2; an annular fluid chamber 68incontinuous coin munication with passageway 40 and disposed between the end wall-32 and confronting face of the valve flange 50'; an annular atmospheric chamber 69'providedbetweeri the end of-the extension 58 flange" 35, cylindrical wall of the tubular casing extension 34an'd "spring encircled portion of the-extension 58 an'd having 'con'tinuous com: munication with the atmospherevia ports 37"and a cup shaped breather or ventingc'ap 70 pressfitted" on'the horizontal collar 'a 6 "with the endwall 71 spaced slightly fromthe'flange 35 and the"- cylindrical wall 72 overlying a portionof the endof' the extension 34"inspace drela- 65 tionship with 'respect toth'e"1atter, said cap"'acting'as" a" battle to filter out foreign"particlesfrorn entering"thfe' chamber 69 an'd alsosilen'c'e' the' ingress of air through the ports 37; the actuating"cylindricahrod 2'4""ha's anorfnal 1 diameter portion"75'- Whicli operably pr'oject'sthr'ough collar 36; the latter acting asa bearing supportthefef and the bores""56;'59 andterminatesatitsfree en'df an enlarged diameter'poitibn' haviri'g' r lolig tudinally spaceri l =groove's '77, 78"'in"its cylindrical sur face and which defines anexternal annular should'er' 79 75 with the normal diameter thereof for an important funcder 79 with an internal annular flange 81, said bushing being of the same length as'the bore 56 and press-fitted therein for movement with the inner valve element 45, and is provided with an internal annular channel 82 between the flange 81 and internal shoulder 60 for reception of a contractible friction sleeve 83 longitudinally split at 84 for continuous frictional engagement around the rod 14 whereby the frictional coefficient normally obtaining between the sleeve 83. and rod portion 75 is of such lea-grime swamp-art lik'' limited r'novenient to the inner valve element 45 as will appear. a

The fixed assembly FA comprises a cylindrical body portion 85 with an external diameter of substantially the same internal diameter as the cylindrical portion of the casing C to accommodate telescopic assembly thereof to nuance are valve'niecl'ianisn'i VM'; external flange 8 6 the deter Buildf the cylindrical 'oniop' s5 and rsrms' her'ewit an erternai i sul r she a z engaged; by the open end of th"e c"asi'ng" C; a c'oir' ndiiig ber of circumferentially e i a llyspaced threaded holes at? provided in the "nd""cal ljfiftlofi 8'5 adj eem the r 8716f receiving in, threaded en agement fer i 89' which piojctf through the holes: lin rical walrwherfeby the easing C and: red in aunitary assembly; the outer "d'd with an annw,

fortlief oiitr trnnnuser are per n85; nan-m ssi bore" 93'lpx'tend's" from the: outer terminu or the body tubular por of the e"ten's'io'n" 58* normally" enga'gesthe warrant ng marginal face portion of the flange 35, as shown Figure 2}"to 'limit the rightward movement of the movable assemblyMAl' Accordingly, the inner facef of'tlie flang'e 35"an'd shoulder9'5 define the limit oflrec'iprocat'ory movemerit of theniovablevaslve assembly MA'fo'r o ening and closing the valve mechanism while the actuating rod 2 4 isfprovid'ed'witlfa predeterminedj'operating stroke of greater length l than the" minute rfecipr'ocation of the nioi/alile assemblyMA, in ac'cldrdanc'e, to iiarn'ple, with V the operating range: of movement of the pedal ztlfwhereby the frictional" engagement between the inner valveeleme nt 45 andactuating rod 24* enables limited reciprocations of the movable assembly at sele'c tedpoints along the fill operating stroke of the pedal '26fwtihinthefextremes 1 theroffor'novel-purposes as will hereinafteriappear.

Th' inrierend: of the valve body portion 8 5 is provided? with an 'an nular' valve seat 98 ir1 '-confrouting 'relatiori'with respecttto the" outer Is'e'at SS OI I 'Eth" outer valve "elemenfi 44 and-nornially slightly" spaed apart a's d pictejd iri d seat 98 mergingat itsfinnernrrg'inaIedge d i b far'jfrdc' il i n 't d s communicat on a pl u'rality of 'longitudiri {passage-i 103'- communicating" with an" annular internal pas s'ag'wa'y l o' t provided iri thesurface'of the'cq nterbore 9 4 v of char'nber 101," tl'1e; {annular space 104 being con cted-t'o' a pliirality of radial passageways 10 6" connected to jan" external annular passageway 107" in 'circiila'r alignin 116 with the assageway- 0a; the latter an"- nular passa way 107 having continuouscommunication g' passageway 42; and preferably flexible: E109 110? connectedirspectively to'the 'fit in s-3'9 as by SHOIf rigid tubes rz; 113; 'to'cen'vey the fluid"actuatingpressuie to the apparatus tobecontrolled by the valve mechanism VM.

'A" marlin-annular" groove 115 being fitted witha split-type radially resilient ring 116 having, for example, one end formed with an inwardly extruded detent portion or ridge 117 for selective engagement in the actuator grooves 77,78 whereby the movable valve assembly MA is releasably stabilized in its two operating positions as shown in Figures 2 and 3. The free end 76 of the actuating rod 24 is slidably supported by and projects through the bore 93 to the exterior of the body portion 85 in coaxial disposition with respect'to the bearing collar 36 to maintain the parts of the valve mechanism in proper operating relationship.

The support S comprises alaterally extending boss 120 integral with the left end of the fixed valve portion 85 as shown in Figure 3. This boss is axially bored at 121 for the reception of a pivot pin 122 in press-fitted relation for oscillation therewith, the outer end of the pin having an 'annular external channel 123. A fixed support or mounting member 124 is provided with a coaxial bore 125 for reception of the outer end of the pin 122 for relative rotative movement with respect thereto, and a cross locking pin 126 is press-fitted through a cross bore 127 in alignment with said channel 123 to freely pass through the latter to prevent lateral displacement of the valve mechanism VM with respect to its support S yet accommodating such oscillatory movement thereof in accordance with the deflection of the actuating rod 24 from a path of straight line movement resulting from the arcuate sweep of the pedal 26 as is understood.

OPERATION As hereinbefore noted, the valve mechanism VM of the present invention is illustrated in Figure l, for explanatory purposes, as incorporated in a servomotor control system designated as a whole SMC. Said system includes, in addition to the structure already enumerated: a vacuum tank T; an internal-combustion engine intake manifold IM; engine carburetor EC and associated throttle valve TV; a fluid control circuit PC for connecting the carburetor EC, tank T via a check-valve CV, valve mechanism VM of the present'invention, and servomotor SM in series; suitable linkage L for mechanically connecting the throttle plate TV with the pivotally mounted accelerator pedal 26 via multiple arm lever ML pivotal-1y mounted on a bracket BR secured as by bolts to the engine compartment side of the vehicle firewall FW; and the expansion spring 28 anchored at one end to the firewall FW and the other end connected to a portion of the linkage for biasing the pedal toward released engine idling position depicted in the figure.

The pedal 26, carburetor EC, tank T, and the servomotor SM are of conventional design, therefore describing these components in structural detail is not believed necessary for a clear understanding of the operation of the control system SMC. However, for a better understanding of the subsequent description of operation, it is believed advisable to alphabetically designate the most pertinent elements.

Thus, the piston of the servomotor SM is designated a; its piston rod is designated b; a normally preloaded compression return spring is indicated a breather cap a; and a pivotal mounting for the unit SM is indicated at e.

The letter s designates a rotatably mounted shaft, the rotation of which in either direction is controlled by the movements of piston rod b, which is shown to have a pivotal connection f with a link g, the latter rigid with one end of said shaft. It is noted that the shaft s is typical of any similar element the rotation of which is responsive to the action of said system under the influence of the valve mechanism VM.

In other words, the shaft s may serve, for example, as the operating element of an automobile braking system, or as the control mem'ber'for a friction clutch. Again, the shaft s may represent a rotatable member for raising and lowering a radio antenna, and so on. It is also noted that the pedal 26 is typical of any suitable means, either .6 a mechanically or manually operable, for imparting reciprocatory motion to the rod 24.

It will be assumed that the shaft s constitutes the control for a conventional friction type clutch of an automotive vehicle. The illustrated servomotor system SMC exhibits the normal status of the included mechanical components when the engine of said vehicle is idling, and the valve device VM open as shown-in Figure 1 with the closed position indicated as by the dashed line position of the pedal 26.

At such time, the valve VM is in open condition whereby the thus established vacuum factor obtaining between the tank T and servomotor SM maintains the piston a rearwardly against the forwardly biasing force of compression return spring 0, as should be apparent. Consequently, assuming that the portrayed vdisposition of link g indicates a clutch-disengaged status, the status quo will continue to obtain so long as the rod 24 is not perceptibly, that is positively activated, in an engine accelerating direction.

In other words, and with particular reference to Figure 2, the shoulder 79 on the actuating rod 24 is in contact with the split friction sleeve flange 81 thus establishing the movable assembly MA in fully retracted position wherein the inner end of the valve extension 58 engages the confronting surface on the inner side of the casing flange 35 to establish said assembly in firm fluid circuit open condition. That is to say, the spring enclosing power chamber of the servomotor SM is evacuated of air to produce the pressure differential on opposite side of the piston a causing the piston to assume the position shown in Figure 1. This evacuating process to activate the servomotor is brought about through the instrumentality of the present valve device VM in the following manner.

With the parts in the positions shown in Figure 2, as a result of the biasing effect of spring 28 on the pedal 26 and connected linkage L, and the rod 24 correspondingly biased therewith, it will be noted that the valve seats 52, 62 are firmly engaging each other in air-tight sealing relationship, while the valve seat 53 isrslightly separated from its mating seat 98 on the fixed body portion 85. Accordingly, the vacuum tank T being continuously in communication with valve chamber 68 via conduit 109 is connected via the separated valve seats 53, 98, annular space 101, passageways 103, annular passageway 104, radial passageways 106, annular passageway 107, thence through the passageway 42 in the fitting 41 to the conduit 1'10 and servomotor vacuum-power chamber to energize the latter as is understood. While the valve parts are in the positions explained above to energize the vacuum servomotor, it should be importantly noted that the biasing force of the spring 28 serves to urge the shoulder 79 on the actuating rod 24 into engagement with the bushing flange 81 carried by the inner valve element 45 thereby operating the movable valve assem bly MA toward the right as viewed in Figure 2. This operation places the valve seats 52, 62 in intimate airtight sealing relationship due to the counter force of the spring 66 and upon seating of the valves 44, 45 as aforesaid they move simultaneously under the influence of the spring 28 to the position of separating the seats 53, 98 as clearly portrayed in Figure 2 wherein the end of the valve extension 58 is in engagement with the inturned flange 35 of the casing C to limit the degree of space between the seats 53, 98. Also it should be noted that with the air controlling seats 52, 62 in engagement, the annular atmospheric space 49 is isolated from the fluid chamber 101 thereby establishing the valve mechanism in open condition.

Closure of the valve mechanism is accomplished by reversal of the operations noted above for opening it. Reference is now made'to Figure 4 wherein the valve parts are shown in their respective positions for establishing closed condition thereof which isolates the vacuum Modified structure and operation Figure illustrates a modified form of the invention in which corresponding parts are designated by like characters of reference distinguished, however, by the addition of the letter a to each numeral and the exponent 1 to each letter, only the open position of the modified movable assembly MA is shown, and it may be assumed that otherwise thecomponents correspond to those of the embodiment first disclosed (Figures 1-4 incl.).

A modified fixed assembly FA is substituted for the assembly FA and comprises a cylindrical body portion 130 forming a unitary assembly with the casing C in the same manner as previously described with the open end of the casing wall engaging the annular shoulder 87a. The inner end of body portion 130 is provided with a projecting arcuate segment 13 1 terminating in an angular end face 132 having a circular recess 133. A sealing washer 134 engages the recess and in the assembled status of the casing C and fixed assembly FA the washer is brought into intimate contact under slight compression with the inner surface of the casing embossment 38a to form an air-tight seal therebetween whereby the passageway '40a in the end wall of the fitting 39a registers with a circular opening 135 through the washer to place the conduit 109a in continuous communication with an aligned longitudinal passageway 136 formed in the segment 131. A fluid chamber 137 is provided by the mergence of the chambers 68, 69 of the first embodiment due to elimination of the valve element 44. This chamber is vented to the atmosphere via ports 37a in the casing flange 35a. The longitudinal passageway 136 intersects a radially disposed passageway 138 in continuous communication with a cross channel 139 in the outer cylindrical surface of the body portion 130. A diametrically opposed radial passageway 140 is provided in the body portion in alignment with the radial passageway 138, and which opens into a cross channel 141 in the opposite surface of the body portion 130, the latter channel having continuous communication with the passageway 42a in the fitting 41a.

The modified movable assembly MA comprises a single cylindrical tubular element 144 having a normal diameter portion 145 with the longitudinal bore 56a and a reduced diameter portion 146 longitudinally bored at 59a to merge coaxially with the bore 56a. The point of mergence between said bores defining the internal annular shoulder 60a in substantially circular alignment with the angular external shoulder 62a, the latter being formerly the ring valve seat 62 in the first embodiment, and the free end of the portion 146 normally engaging the inner marginal face of the flange 35a to limit the rightward movement of said element 144 wherein open condi tion of the valve mechanism VM is established as portrayed in the figure. Formed in the exterior surface of the portion 145 medially thereof is an annular passageway 148 normally connecting theradial passageways 138, 140 whereby the conduits 109a, 110a are connected via washer opening 135, passageway 136, radial passageway 138, annular passageway 148, radial passageway 140, cross channel 141, and passageway 42a, to place the valve mechanism VM in open condition when the pedal 26a is in its fully released position as shown in Figure 1. A valve land 150 projects from a lower side portion adjacent the annular passageway 1'48, and extending from the opposite side of said land is a longitudinal surface channel 151 opening into the chamber 137 thereby placing this channel in constant communication with the atmosphere via the openings 37a in thecasing flange 35a and breather cap 70a. This valve land being operative for selectively placing the annular passageway 148 and channel 151 in communication with the radial passageway 140 to establish open and closed conditions respectively of the valve device VM To maintain the slidable valve element 144 from relative rotative movement so that the channel 151 will ,1 register with the radial passageway 140 for communicat ing therewith, a lug .153 is struck from the circular edge of the extreme end of the collar 36a, and which engages a longitudinal surface groove 154 in the actuating rod 24a to thus prevent rotative movement of the rod but accommodating slidable movement thereof, and the reduced diameter portion 146 of the tubular valve element 144 is provided with a press-fitted pin 155 through the wall thereof into engagement with groove 154 to thus prevent relative rotative movement between the element 144- and rod 24a. In this way the slidable element 144 is maintained in proper position so that when reciprocated responsive to like actuations of the rod 24a, the atmospheric channel 151 will connect the inner end of the radial passageway 140 to atmosphere in the closed position or" the valve device VM The valve element portion 145 carries the press-fitted bushing 8011 with the flange 81a to form the internal annular channel 82a with the internal shoulder 60a for reception of the split contractible friction sleeve 83a in the same manner and for the same purpose as described in connection with the first embodiment Figures 1-4 inclusive. The shoulder 95a is engaged by the inner end of valve member portion 145 to limit the leftward move- 'ment of the slidable valve element 144 whereby the limit of reciprocative movement is defined, by the opposite end of the extension 146 engaging the flange 35a to limit the rightward movement thereof.

In operation, this modified structure operates in the same manner as already described in connection with the operation of the first embodiment responsive to minute reciprocations of the actuating rod 24a by the pedal 26a at substantially all points intermediate the extremes of the fully operating movement of said rod and pedal, to open and close the valve VM The split friction sleeve 83a moves the valve element 144 simultaneously with the rod 24a to the open position shown in Figure 5 wherein the end of the extension 146 engages the flange 35a and the annular passageway 148 connects theradial pas' sageways 138, 140 and in the opposite direction to place the atmospheric channel 151 in communication with the conduit 110a and to cut off communication between the radial passageways 138, 140 to establish the parts in closed disposition.

As will be appreciated this modified construction requires slightly longer reciprocative movements of the valve element 144 to connect and disconnect the conduit a with respect to the tank T since such operating movement must include the added distance of the width of the valve land 150 required to place this land out of registry with the radial passageway to open the valve as is understood, however, there is a simplification of the structure produced with attendant lower production cost than the valve device of the first embodiment. This modified valve may have, as also in the case of the first embodiment, two open positions in lieu of the illustrated open and closed positions according to the fluid circuit control involved. Accordingly, in the broader patent sense the two illustrated positions will be referred to as two operating positions without limitation as to their respective specific purposes. 1

Operational summary From the foregoing, it should be manifest that the present valve mechanism simulates a follow-up control from the pedal 26 to the power apparatus SM as described for controlling an automotive friction clutch. As the pedal is depressed the clutch correspondingly engages with slight release of the pedal causing instant disengagement of the clutch at any point along the full operating range of the pedal. After the clutch has become fully engaged, a disabling valve (not shown) may be included in the fluid control circuit FC to overrule further effectiveness of the present valve mechanism VM whereby the clutch remains engaged irrespective of pedal manipulation until all-disengagement thereof isrequired as in bringing "the vehicletov a.stop or to facilitate change .of speed ratio inwtheassociated gearbox (not shown). The present. in? vention contemplates supplemental. control of the, valve mechanismYM in response to shift-lever movements to enablerstoppingthe vehicle by. setting the shift-lever in neutralpositio-nwith.returriof the lever to a gearaengaged position transferring the. control of the valve mechanism to accelerator pedal operation tq..s tart the vehicle, and thereafter,..the.. latter operation being disabled while the vehicleis underway until a change of gear ratio or stoppingathe' vehicle isdesired, suchrequiring theclutch members. .to .-be. separated .to.interrupt torque transferal to .thedriving wheels ofthe vehicle as is understood.

It is .also .obvious. from the. .two. disclosures herein made, that the operation of thevalve portrayed in Figures .leA-inclusive may. be more sensitized for a correspondingly-shorterreciprocatingstroke ofthe rod 24 than obtainable from the modified disclosure in Figure since the, former constructionrequires.onlysuch movement ofihevalve element 44, .45 as to effect face contact and separation thereof to produce the open and closed positimtsthereof;v hileinthelatter. construction, the valve lands150 width must .be added tothe overall actuating movement of. the slidable valve element 144 in establishing theopen and closed positions thereof. V

Referring .to. the terminology used in the. foregoing description and in the appended claims, the identifying expressions and/orterms employed are intended to convey meaningswhich include the range of reasonable equiv valents in thepatent sense. For example, the expressiQns.,f II 1ovable assembly, movable valve elements, ffiXcd assembly, ,fixed valve element, are intended to include anystructure providing for relative mo'vement of.,fixed .and, movableelements whether such assembly.

providesfor sliding or rotative movement of the elements, Ora. different type of movement serving the same purpQse-to-open and close the assembly; the terms, right, ffleftfi horizontaL. vertical, angular, depending, ...1 P-Pri .lowel'fi. fbottom/Z top, and other directional WQrdsor characters are intended to have only relative connotation for. convenience in describing the structure as. illustrated, andare not intended to be interpreted as establishing a definite operating position of the valve mechanism VM or requiring, any particular orientation With'IeSpect to related structure .of the present disclosure. .;.,..Fr,om the-foregoing description. augmented by an inpection of. the drawings, it should be manifest that my invention provides a novel switch mechanism which is pa ticularlyadaptednfor. incorporation in a servomotor controlsystemand thelike. 7 ,,,,.Ho wever, it is tobe understood that. the illustrated and deseribedacontrol system has. been given by way of example,;only,...and.notina limiting sense. In said exemplary system, the pivotal mounting S is obviously requ site. Such anarrangement,may. not be necessary Should the. actuating rod 24 .be reciprocated along a constant.plane., .v Theltefiore, 1 do not desire to be restricted to the precise details illustrated and described, my invention contemplating any and all modificationsand arrangements thereof, and such equivalents as may fall Within the scope of the appended claims. Y

I Having thus. described my invention, I claimz T, 1 In a valve-:mecha nismincluding a double-ended c n .anda pair ofrelatively movable telescopically.- relatediel-e ment s therein having cooperating seatsnormallyfengaged ga concentric seat on one of said elements; a fixed co pe ting seat no hv spa ed f aidwn enhi h s fl Chamber spo d. et n he. pair of s a /s ts lafi aidt a P r tabl ng continuous c m unication between the chamber andfiX-ter-ior pf the ca another fluid cham er .isp ed betw en. the one slshtenaa dsasins, a P t.r fi ablishii g.c utinuousacomr mnnication bet-ween the exterior of the casing and the last-mentioned. chamber, anormally preloaded compression sp op rably d po ed be een said, p i of I val elements urging thclni to seatedfel ationship with toc ch 0 r, paSsas WarcQhm .j st-t iof. ite ng S s, apa for est b continuous 'c njcatio betweenlheexterior' f casin ss wav, a hsit di o er e em. nt .0a Ta ly disposedwi h e pe t f9 n sa fc erhre m ging with ai long tu. 'nal' aiiially aligned circular openin 's through the e nds of v l e c n ana tu o d opera yjp iecti ne en of h exte r. f h jcasin' th ou h nines and bores aforesaid t the exter or o the, 'c ng'at the oppo t a radia ly o ac i e sp it Yp'e slev circling said rod in continuous frictio' l enga g'ement therewitha'nd 'di posed in cular 'alignm t with the surface Ofthe counter'b'ore', an in frnalann er" in P ovide at he p int of .r 'wr'gcn e betw n the res aforesaid t 1232 one nd o 'srlit l eve; an 'ht iia annularsh u der defining t e O ter terminu f hs co nterbb e. iiase t the the nd of the sp i s eeve to t s p v' hta ial .ac rnent of the Spl t sleevew h respect 1Q he c th r' 'lemienh a en a d d am ter tion on the rod defining an annular shoulder therewit .9 fe hl mited r tract n i ve en of d r d an val e elements toward their respective fully retracted pos wherein the pair of elements is in seated relation and the one element'spajced fromits fixed seat, and means for actuating said aptuator rod. v I

v Ihe mhau smacc fdi g to cl i i w h the counterbore is press-fitted with a cylindrical sleeve terminating at its outer end with lan internal annular h, j t p v d an intern annula Sp c Wit the opposite endofthe counterbore confronting said a in shou r, ai a n a Space rc iv g ai coht actihlje s ve for ad l movement only relatively thereto bet e d p d annu a shou ders.

Th a vemegh sm din t C aim 2 n u n a pair of longitudinally spaced grooves. provided in the surface of theenla'rged diameterof the rod for selective engagementhy a yield-able detent carried by the valve casing to releasably establish the movable valve elements in their respective operating positions corresponding to open and closedcondition. I 4. The valve mechanism according to claim 3 i ing a longitudinal bore merging with .CQQnter through the fixed valve seat in coaxial disposition] 1th respect to the axis thereof for slidablysupp o gf tion of the other valve elemen tran internal ann ar shoulder at the point of mergence between said mentioned longitudinal bore and counterbore, for'en'g ment by the confronting end of the other'valve ele' w e fm' v d; an huu arh edu ed, .di n erjn ioje'ction disposed on the opposite end of the valve casing in coaxial disposition therewith; an intur'ned annular defining the terminus of said projection and marglnal edge of the opening through which the a tuator .fOd projects for engagement by the oppositeend of thefother valve element when fully released whereby 'th'e'limits "of thetreciprocatory movement of the pair of valve elements is established. 7 g V 5. The valve mechanism according to claim 4 includ ing a laterally projectingpin journaled in ajsuitable fixed aperture for mounting the mechanism in operation position.

6. In a valve mechanism comprising: a ho llow valve port establishing continuous communication between one of said chambers and the exterior of the valve body; another port establishing continuous communication between the other chamber and the exterior of the valve body; a third fluid chamber disposed between the one valve element and one end of the valve body; a port establishing continuous communication between the exterior of the valve body and said third chamber; a passageway establishing continuous communication between the third chamber and the chamber between said valve elements; a normally preloaded compression spring carried by the other element for biasing the one element into seated relation with the other element; another normally preloaded compression spring for biasing both valve elements into normal released position wherein the outer concentric seat is spaced from its fixed seat placing the pair of chambers in communication with each other, and the cooperating seats between the valve elements in seated relation to isolate the pair of chambers from the third chamber; reciprocative means coaxially disposed with respect to said valve elements for moving them; and a friction element incorporated in said reciprocative means and operable in response to minute reciprocations of the latter at any selected position intermediate the limits of the full operating stroke thereof for moving said valve elements to establish fluid communication between the three mentioned ports.

7. In a valve mechanism for controlling a fluid circuit including a valve body having a fixed annular seat therein; a pair of telescopically-related valve elements movable relatively with respect to each other and together; inner and outer concentric valve seats carried on opposite sides of one of said valve elements, said outer seat cooperating with said fixed seat; an annular concentric valve seat carried by the other valve element cooperating with the inner confronting concentric seat on the one valve element; means for normally biasing said pair of valve elements into seated relationship with respect to each other and the one valve element spaced from the fixed seat; a fluid chamber disposed between the one valve element and fixed seat in continuous communication with a passageway leading to the exterior of the easing; a second fluid chamber disposed between the pair of valve elements and confronting valve seats thereof in continuous communication with a passageway leading to the exterior of the casing; a third fluid chamber disposed between the pair of valve elements and one end of the casing in continuous communication with a passageway leading to the exterior of the casing; reciprocatory means for moving said pair of valve elements out of engagement with respect to each other to establish their confronting seats in spaced relationship and the outer seat into engagement with the fixed seat to isolate the firstmentioned chamber from the third chamber and to connect the latter chamber with the second chamber; and a friction element operable in response to minute reciprocations of the reciprocatory means at any selected position intermediate the limits of the full operating stroke thereof for alternately moving said pair of valve elements into and out of engagement with respect to the fixed seat and the confronting seats thereof to open and close said fluid circuit respectively.

8. In a valve mechanism for controlling an associated fluid circuit including a hollow valve body having longitudinally spaced end walls and a pair of ports leading from the hollow of the valve body in continuous communication with the exterior of the valve body; a reciprocable valve assembly movable within the hollow of the valve body relatively to said pair of ports for controlling the latter; a longitudinal bore through the valve assembly having an intermediate annular space of larger diameter defining an internal annular shoulder at each end thereof; a pair of axially aligned circular openings provided in the end walls of the valve body and concentrically disposed with respect to said longitudinal bore; a reciprocative element projecting through the wall openings of the valve body and said longitudinal bore in the valve assembly; a contractible longitudinally split friction sleeve confined between said pair of internal annular shoulders for axial movement with the valve assembly and encircling said reciprocative element in continuous frictional engagement therewith; means for com tinuously biasing the valve assembly toward connecting said ports; and means for imparting minute reciprocations to the reciprocative element at any selected position intermediate the limits of the full operating stroke thereof for alternately moving the valve assembly to connect and disconnect said pair of ports resulting in the associated fluid circuit being opened and closed respectively.

9. The valve mechanism according to claim 8 including an internal annular channel in the surface of the valve body hollow spaced from the valve assembly in normal port connecting disposition; a split resilient retainer ring engaging said channel for engagement by the confronting end of the valve assembly when moved by said last-mentioned means; and an inturned annular flange provided on the marginal portion of the opening through the opposite end wall of the valve body for engagement by the opposite end of the valve assembly when in normal port connecting disposition whereby the reciprocative movement of the valve assembly is limited.

10. The valve mechanism according to claim 9 including a plurality of ports through the wall of said inturned flange for maintaining communication between a portion of the interior of the valve body and the exterior thereof; and a venting cap mounted on said opposite end wall of the valve body and spaced from said plurality of ports for preventing foreign particles from entering said interior of the valve body.

11. The valve mechanism according to claim 10 in which the free end of the reciprocative element is provided with a larger diameter to produce an external annular shoulder with the normal smaller diameter thereof, said larger diameter projecting through the opening in the end wall of the valve body correspondingly enlarged to accommodate the same, and said shoulder normally engaging the confronting end of the valve assembly to releasably maintain the latter in port connecting disposition wherein the opposite end of the valve assembly is engaged with the inturned flange of the opposite end wall of the valve body.

12. The valve mechanism according to claim 11 including a laterally projecting pin journaled in a suitable fixed aperture for mounting the mechanism in operating position.

References Cited in the file of this patent UNITED STATES PATENTS 2,617,445 Elder Nov. 11, 1952 2,775,260 Drennen Dec. 25, 1956 2,807,239 Grant Sept. 24, 1957 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.s 2,908,253 v gotg 3, 1959 Glenn To Handel It is hereby certified that error appears in the printed specificatio: of the above numbered patent requiring correction and' that the said Letter: Patent should read as corrected below.

Column 6, line 30, for "side" read em sides column ll, line 21, for "element" Peed w elements line 49, for "switch" read valve column 12', line 36, for "relatively" read relative line 64, for "operation" read operating vsigned and sealed. this 19th day of April 1960,

(SEAL) Attest:

KARL AXLINE ROBERT C. WATSON Attesting Oflicer Commissioner of Patents 

